//https://leetcode.cn/problems/design-circular-queue/

typedef struct {
    int* a;
    int front;
    int rear;
    int k;

} MyCircularQueue;


MyCircularQueue* myCircularQueueCreate(int k) {

    MyCircularQueue* obj = (MyCircularQueue*)malloc(sizeof(MyCircularQueue));
    if (obj == NULL)
    {
        perror("malloc fail\n");
        return NULL;
    }
    obj->a = (int*)malloc(sizeof(int) * (k + 1));
    if (obj->a == NULL)
    {
        perror("malloc fail\n");
        return NULL;
    }

    obj->front = 0;
    obj->rear = 0;
    obj->k = k;

    return obj;

}

bool myCircularQueueIsEmpty(MyCircularQueue* obj) {

    return obj->front == obj->rear;

}

bool myCircularQueueIsFull(MyCircularQueue* obj) {

    return (obj->rear + 1) % (obj->k + 1) == obj->front;

}

bool myCircularQueueEnQueue(MyCircularQueue* obj, int value) {

    if (myCircularQueueIsFull(obj))
    {
        return false;
    }

    else
    {
        obj->a[obj->rear++] = value;
        obj->rear %= (obj->k + 1);    //防止尾的下一个溢出
        return true;
    }

}

bool myCircularQueueDeQueue(MyCircularQueue* obj) {

    if (myCircularQueueIsEmpty(obj))
    {
        return false;
    }

    else
    {
        obj->front++;
        obj->front %= (obj->k + 1);
        return true;
    }

}

int myCircularQueueFront(MyCircularQueue* obj) {

    if (myCircularQueueIsEmpty(obj))
    {
        return -1;
    }

    else
    {
        return obj->a[obj->front];
    }


}

int myCircularQueueRear(MyCircularQueue* obj) {

    if (myCircularQueueIsEmpty(obj))
    {
        return -1;
    }

    int x = obj->rear == 0 ? obj->k : obj->rear - 1;

    return obj->a[x];

}

void myCircularQueueFree(MyCircularQueue* obj) {

    free(obj->a);
    free(obj);

}
